London clock

i read this problem shortly after it was posted. it appeared too simple.when i noticed that the long hand was longer than the clock radius i decided not to reply.there still appears to be some confusion.
i offer the following
a trig function of any angle will equal plus or minus that same function of the corresponding acute angle.the corresponding acute angle of 120 degrees is 60 degrees and the angle is in the second quartrant where x is negative and y positive. sign of 60 is .866, cosine is -.5

london clock

problem with linear speeds ?
problem with trig functions for angles greater than 90 degrees?
if latter then you need to learn how to convert these angles into corresponding acute angles.suggest you go into google for trigonometric functions.there are various web sites explaining how this is done on a coordinate diagram using a unit circle at 0,0

london clock

radius of clock is 3.5 m.long hand should be shorter than that. lets say its 3.4 m
tips of hands travel along concentric circles each with a radius equal to the hands length. each complete revolution travels a distance 2 pi r
long hand 2pi3.4 or 21.4m. short hand 2pi2.7 or 17 m.
long hand makes one rev every 60 minutes, speed is 21.4 /60 =.36m/min
short hand makes one rev every 12 hrs or 720 min. speed is17/720=.024 m/min